The present invention generally relates to a splice closure for protecting spliced communication cables. More particularly, this invention relates to a reenterable and reusable splice closure.
The telecommunications industry utilizes cables comprising numerous individual conductors, such as copper wire or fiberoptic conductors. In the laying of the communications cables, it is often necessary to splice sections of these cables. Also, the communication cables sometimes get damaged during their use due to a variety of factors, such as high wind, storm, snow, etc. When they are damaged, it is necessary to splice together the damaged sections of the cable. Typically, a splice closure is positioned around the splice to protect the exposed conductors from the elements, and also to protect the splice from the lateral and vertical forces.
A reference may be made to U.S. Pat. No. 3,337,681 for a description of a prior art splice closure. Such splice closure includes a protective tubular case comprising two semicircular half tubular members, with circular end seals disposed inside the tubular case at each end. Each of the end seals, in turn, comprises two semicircular half end seals, and are configured to form a longitudinal cavity through which cables enter the protective case to form a splice. A liner made from a flexible material, such as Neoprene, is bonded to the inside surface of the tubular case. The liner seals the joints between the two half tubular members and between the end seals and the tubular case.
The present invention relates to an improved splice closure with fewer parts, relatively inexpensive to manufacture, easy to assemble and disassemble-especially in the field and capable of being sealed, unsealed and resealed.
According to the present invention, the splice closure includes a tubular protective case comprising back and front covers. The left and right ends of the back cover are configured to form integrally therewith left rear and right rear half end seals, which are adapted to mate with separately-formed, left front and right front half end seals. The left front and right front half end seals are formed to fit inside the left and right ends of the front cover. The separately-formed, left front half end seal is secured to the integrally-formed, left rear half end se with a first set of cables clamped between the mating surfaces thereof. Likewise, the separately-formed, right front half end seal is secured to the integrally-formed, right rear half end seal, with a second set of cables clamped between the mating surfaces thereof. The two sets of cables are spliced together and the front cover is bolted in place over the back cover/spliced cables/end seal assembly to form the protective case. Before the two covers are bolted together, a sealant is disposed between the mating surfaces of the front and back covers and between the outer surfaces of the left front and right front half end seals and the interior surfaces of the front cover to prevent extraneous material, such as water, dust, debris, snow, etc. from entering the protective case.
In the preferred embodiments, the mating surfaces of the two covers are formed to include a longitudinal sealing groove, and the outer peripheral surfaces of the separately-formed, left front and right front half end seals and the inner peripheral surfaces of the front cover are formed to include a circumferential sealing groove. A strip of composite sealing material, comprising a substantially non-tacky, resilient and yieldable sealant attached to an adhesive substrate, is disposed in the longitudinal sealing grooves in the back cover and in the outer circumferential sealing grooves in the left front and right front half end seals to seal the respective joints. The composite sealing material is disposed in the longitudinal and circumferential sealing grooves with the adhesive substrate contacting and adhering to the sealing grooves and with the non-tacky sealant facing away from the sealing grooves. This facilitates removal of the front cover from the back cover/spliced cables/end seal assembly for repairs or inspection without damaging the sealant. Upon completion of the work, the front cover is merely re-bolted in place.
In further preferred embodiments, the longitudinal grooves in the two covers have a wave-form cross-section to compensate for the variation in pressure that occurs when the two covers are bolted together.
In still further preferred embodiments, the end sections of the cables are first wrapped with a narrow strip (about 1/2 inch wide) of soft and sticky sealing material (such as mastic sealant), then wrapped with a sizing tape (about 4 inches wide) and then finally with a strip of composite sealing material (about 1 inch wide) (with the adhesive substrate contacting and adhering to the sizing tape) before the cables are clamped between the respective half end seals.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.